Exam 9: Lipids and Membranes

Lipid-anchored membrane proteins that link to an isoprenoid chain via the sulfur atom of cysteine are called proteins.

Match each technique with its purpose." A) separate groups of neutrallipids B) diacylglycerolseparation based on chain length and degree of unsaturation C) Lateral movement of proteins in cell membranes D) Separate fatty acid esters E) Separate neutrallipids and phospholipids -thin layer chromatography

Valinomycin is an antibiotic that kills bacteria by surrounding K⁺ ions and shuttling them down their concentration gradient and across membranes. Which might be a cause of cell death?

The membrane transport protein Na⁺-K⁺ ATPase carries both Na⁺ and K⁺ ions across the plasma membrane. Typically the concentration of K⁺ inside cells is about 30 times higher inside the cell than outside. The concentration of Na⁺ is about 20 times less inside the cell than outside. Based on this information, which statement below is false?

Symport and antiport proteins must be active transport proteins.

Vitamins A, E and K are all isoprenoids.

A fatty acid designated as 20:0 is , while one that is designated 20:3 D^5,8,11 is .

Plasma levels of cholesterol and triglycerides are elevated by

Most bacteria do not have sphingolipids or steroids.

An unknown lipid is treated with a mixture of phospholipases A₁, A₂, C and D. Since no glycerol is formed after this treatment, the lipid is most likely

are the simplest lipids but they may be a part of or a source of many complex lipids.

Cholesterol accounts for 20% to 25% of the mass of lipids in a typical mammalian plasma membrane.

When red-blood cells are treated extensively with protease most membrane proteins are broken down into small peptides. However, some proteins are very resistant to this treatment. If cleavage by protease is the only type of reaction that occurs in this treatment, how is this explained?

The distribution of peripheral membrane proteins is generally identical on both sides of a given membrane.

Ethanolamine, serine and choline can be cleaved from glycerophospholipids by treatment with

Which does not generally use a signal transduction mechanism?

Which statement is false about lipid-anchored membrane proteins?

Another name for facilitated diffusion is .

Why should it not be surprising that for many cells water requires a protein for its transport across a membrane?

Which does not apply to the diffusion of O₂, CO₂ and small hydrophobic molecules across a membrane?